Table 1.
Modulation of G protein‐coupled receptors by amiloride and amiloride analogs. The given values reflect a) inhibitory potency or affinity for ligand displacement in radioligand binding assays or inhibition of ligand‐induced receptor activation in functional assays, b) modulatory potency of their effect on radioligand dissociation, and c) fold change of dissociation rates of orthosteric ligands. References are in numbered superscript
| Receptor | Orthosteric ligand antagonist; agonist | Amiloride (analog) | Inhibitory potency or affinity a ‐ Displacement of orthosteric ligand by amiloride (analog) in IC50 or Ki ± SEM (µM) | Modulatory potency ‐ Concentration‐effect on dissociation of orthosteric ligand by amiloride (analog) in EC50 ± SEM (µM) | Effect on dissociation of orthosteric ligand by 100 µM b amiloride (analog) in koff/koff(control) > 1, Increase < 1, Decrease |
|---|---|---|---|---|---|
| Adenosine A1 | [3H]DPCPX | Amiloride | 2.0 ± 0.2B24 | … | 1.5Rd26 |
| 197 ± 23R26 | |||||
| Benzamil | 0.65 ± 0.04B24 | … | … | ||
| CBDMB | 1.2 ± 0.1B24 | … | … | ||
| DCB | 1.6 ± 0.1B24 | … | … | ||
| DMA | 8 ± 2R26 | … | 1.9R26 | ||
| HMA | 0.41 ± 0.03B24 | … | 1.7R26 | ||
| 22 ± 4R26 | |||||
| MBA | 0.070 ± 0.004B24 | … | … | ||
| MGCMA | 22 ± 1B24 | … | … | ||
| MIBA | 0.16 ± 0.01B24 | … | … | ||
| 13 ± 1R26 | |||||
| Phenamil | 1.5 ± 0.1B24 | … | … | ||
| [ 3 H]PIA | Amiloride | 2.4 ± 0.1B24 | … | No effectRd26 | |
| Benzamil | 0.85 ± 0.03B24 | … | … | ||
| CBDMB | 4.0 ± 0.4B24 | … | … | ||
| DCB | 2.7 ± 0.2B24 | … | … | ||
| DMA | … | … | No effectR26 | ||
| HMA | 0.50 ± 0.03B24 | … | No effectR26 | ||
| MBA | 0.09 ± 0.01B24 | … | … | ||
| MGCMA | 16 ± 1B24 | … | |||
| MIBA | 0.20 ± 0.01B24 | … | … | ||
| Phenamil | 2.3 ± 0.1B24 | … | … | ||
| Adenosine A2A | [3H]ZM‐241,385 | Amiloride | 9.7 ± 1.1R25 | … | 1.2Rd25 |
| Benzamil | 2.2 ± 0.3R25 | … | 2.4Rd25 | ||
| HMA | 3.3 ± 0.5R25 | … | 12Rd25 | ||
| MGCMA | 89 ± 13R25 | … | 1.2Rd25 | ||
| MIBA | 3.0 ± 0.2R25 | … | 5.7Rd25 | ||
| Phenamil | 2.6 ± 0.4R25 | … | 1.9Rd25 | ||
| [ 3 H]CGS‐21,680 | Amiloride | … | … | No effectRd26 | |
| DMA | … | … | No effectR26 | ||
| HMA | … | … | No effectR26 | ||
| Adenosine A3 | [3H]PSB‐11 | Amiloride | 82 ± 7H26 | … | No effectHd26 |
| DMA | 13 ± 2H26 | … | 1.3H26 | ||
| HMA | 6 ± 1H26 | … | 2.3H26 | ||
| MIBA | 8 ± 1H26 | … | 1.6H26 | ||
| [ 125 I]I‐AB‐MECA | Amiloride | >100R26 | … | No effectHd26 | |
| DMA | 20 ± 3R26 | … | 0.80 H26 | ||
| HMA | 7 ± 1R26 | … | 0.53 H26 | ||
| MIBA | 7 ± 2R26 | … | 0.59 H26 | ||
| α1A‐Adrenergic | [3H]Prazosin | Amiloride | 11 ± 2H37 | … | 1.2H37 |
| Benzamil | 0.8 ± 0.1H37 | … | 1.7H37 | ||
| DMA | 0.82 ± 0.03 H37 | … | 1.5H37 | ||
| EIA | 2.7 ± 0.3 H37 | … | 2.2H37 | ||
| HMA | 1.1 ± 0.2H37 | … | 5.5H37 | ||
| MIBA | 0.49 ± 0.07H37 | … | 2.4H37 | ||
| α2A‐Adrenergic | [3H]Yohimbine | Amiloride | 30 ± 2H42 | … | 2.0He42 |
| A‐EIA‐AS | … | 40P41 | >1P41 | ||
| Benzamil | 3.5 ± 0.7H42 | … | No effectHe42 | ||
| DMA | 3.6 ± 0.1H42 | … | 5.3He42 | ||
| [3H]Rauwolscine | … | … | 6.3He42 | ||
| [3H]RX‐821,002 | … | … | 7.1He42 | ||
| [3H]Yohimbine | EIA | 1.7 ± 0.2H42 | 50P41 | >1P41 | |
| 155He42 | |||||
| HMA | 0.21 ± 0.00H42 | … | 138He42 | ||
| [3H]Rauwolscine | … | … | 57He42 | ||
| [3H]Yohimbine | MIBA | 0.56 ± 0.01H42 | … | 101He42 | |
| [ 3 H]UK‐14,304 | Amiloride | 25 ± 0.2H43 | … | 0.67 He43 | |
| DMA | 3.2 ± 0.2H43 | … | 0.77 He43 | ||
| HMA | 0.18 ± 0.02H43 | … | 0.37 He43 | ||
| α2B‐Adrenergic | [3H]Rauwolscine | CBDMB | … | … | <1 R44 |
| EIA | … | … | >R44 | ||
| MIBA | … | … | >1R44 | ||
| β1‐Adrenergic | [125I]Iodocyano‐pindolol | Amiloride | 83 ± 14R36 | … | … |
| β2‐Adrenergic | [125I]Iodocyano‐pindolol | Amiloride | 60R36 | … | … |
| CCR2 | [3H]INCB3344 | Amiloride | No effectHf45 | … | … |
| Benzamil | No effectHf45 | … | … | ||
| HMA | 79H45 | … | 1.25H45 | ||
| MCGMA | No effectHf45 | … | … | ||
| MIBA | 158H45 | … | … | ||
| Phenamil | No effectHf45 | … | … | ||
| [3H]CCR2‐RA‐[R] c | Amiloride | No effectHf45 | … | … | |
| Benzamil | No effectHf45 | … | … | ||
| HMA | 79H45 | … | 1.36H45 | ||
| MCGMA | No effectHf45 | … | … | ||
| MIBA | 126H45 | … | … | ||
| Phenamil | No effectHf45 | … | … | ||
| [ 125 I]CCL2 | HMA | … | … | 9.7H45 | |
| Dopamine D1 | [3H]SCH‐23,390 | Amiloride | 49 ± 1H50 | >1000H50 | … |
| Benzamil | 1.6 ± 0.5H50 | 74 ± 8H50 | … | ||
| MIBA | 4.4 ± 0.2H50 | 13 ± 1H50 | 26He50 | ||
| Dopamine D2 | [125I]Epidepride | Amiloride | … | … | 2.5Ri51 |
| [3H]Spiperone | 390 ± 4H50 | 215 ± 35R53 | 1.5Ri51 | ||
| … | 100 ± 10H50 | 2.7Rj53 | |||
| Benzamil | 25 ± 2H50 | 46 ± 4R53 | 4.8Rk53 | ||
| 29 ± 7H50 | |||||
| DMA | … | 76 ± 8R53 | 8.4Rk53 | ||
| EIA | … | 20 ± 5R53 | 18Rl53 | ||
| HMA | … | 10 ± 2R53 | 16Rl53 | ||
| MIBA | 6.6 ± 0.4H50 | 14 ± 1R53 | 14Rl53 | ||
| 2.1 ± 0.2H50 | 88He50 | ||||
| Dopamine | Amiloride | 29Rm54 | … | … | |
| DMA | 1.4Rm54 | … | … | ||
| MIBA | 0.9Rm54 | … | |||
| 0.6 ± 0.2Hn50 | |||||
| Dopamine D3 | [3H]Spiperone | Amiloride | 120 ± 7H50 | 43 ± 3 H50 | … |
| Benzamil | 16 ± 1H50 | 15 ± 2H50 | … | ||
| MIBA | 1.7 ± 0.1H50 | 0.29 ± 0.14H50 | 18He50 | ||
| Dopamine | MIBA | 1.8Ro54 | … | … | |
| Dopamine D4 | [3H]Spiperone | Amiloride | 280 ± 30H50 | 420 ± 4H50 | … |
| Benzamil | 6.1 ± 0.4H50 | 28 ± 2H50 | … | ||
| MIBA | 1.3 ± 0.2H50 | 22 ± 5H50 | >1He50 | ||
| GnRH | [ 125 I]Triptorelin | Amiloride | >100H63 | … | … |
| Benzamil | >100H63 | … | … | ||
| DCB | 30 ± 3 H63 | … | 1.7H63 | ||
| MIBA | 39 ± 7H63 | … | 2.1H63 | ||
| HMA | 29 ± 3 H63 | 49 ± 7H63 | 2.5H63 | ||
| MCGMA | >100H63 | … | … | ||
| Phenamil | >100H63 | … | … | ||
| Histamine H1 | [3H]Mepyramine | Amiloride | >10R21 | … | … |
| Benzamil | 3.2 ± 0.2R21 | … | … | ||
| HMA | 5.6 ± 1.2R21 | … | … | ||
| Muscarinic M1 | [3H]Pirenzepine | Amiloride | >10R21 | … | … |
| Benzamil | 2.9 ± 0.7R21 | … | … | ||
| HMA | 3.6 ± 1.0R21 | … | … | ||
| Muscarinic M2 | [3H]N‐methyl‐scopolamine | Amiloride | >10R21 | … | … |
| Benzamil | 5.8 ± 1.1R21 | … | … | ||
| HMA | 2.9 ± 0.5R21 | … | … | ||
| Muscarinic M3 | [3H]N‐methyl‐scopolamine | Amiloride | 50R67 | … | … |
| Benzamil | 2.8 ± 0.5R21 | … | … | ||
| HMA | 4.7 ± 0.8R21 | … | … | ||
| Acetylcholine | Amiloride | 478Rq65 | … | … | |
| δ‐Opioid | [ 3 H]DADLE | Amiloride | >10R21 | … | … |
| Benzamil | >10R21 | … | … | ||
| HMA | 1.0 ± 0.2R21 | … | … | ||
| κ‐Opioid | [ 3 H]Ethyl‐ketazocine | Amiloride | >10R21 | … | … |
| Benzamil | >10R21 | … | … | ||
| HMA | 3.9 ± 0.6R21 | … | … | ||
| µ‐Opioid | [3H]Naloxone | Amiloride | >10R21 | … | … |
| Benzamil | 1.1 ± 0.4R21 | … | … | ||
| HMA | 0.06 ± 0.02R21 | … | … | ||
| Serotonin 5‐HT1A | [ 3 H]8‐OH‐DPAT | Amiloride | >10R21 | … | … |
| Benzamil | 1.9 ± 0.3R21 | … | … | ||
| HMA | >10R21 | … | … | ||
| Serotonin 5‐HT1B | [ 3 H]5‐Carboxa‐midotryptamine | Amiloride | 20H73 | … | … |
| Sumatriptan | 35Hs73 | … | … | ||
| [ 3 H]Serotonin | Benzamil | >10R21 | … | … | |
| [ 3 H]5‐Carboxa‐midotryptamine | EIA | 13H73 | … | … | |
| [ 3 H]Serotonin | HMA | >10R21 | … | … | |
| Serotonin 5‐HT1C | [ 3 H]Serotonin | Amiloride | >10R21 | … | … |
| Benzamil | >10R21 | … | … | ||
| HMA | 6.7 ± 1.2R21 | … | … | ||
| Serotonin 5‐HT1D | [ 3 H]Serotonin | Amiloride | >10R21 | … | … |
| Benzamil | >10R21 | … | … | ||
| HMA | >10R21 | … | … | ||
| Serotonin 5‐HT2 | [ 3 H]Serotonin | Amiloride | >10R21 | … | … |
| Benzamil | 1.4 ± 0.1R21 | … | … | ||
| HMA | 0.40 ± 0.06R21 | … | … |
Abbreviations: B, bovine receptor; CBDMB, 5‐(N‐4‐chlorobenzyl)‐2',4'‐dimethylbenzamil; c, in presence of 100 µM amiloride (analogue) except when stated otherwise; d, in presence of 1 mM amiloride (analog); DCB, 3',4'‐dichlorobenzamil; DMA, 5‐(N,N‐dimethyl)amiloride; e, calculated for the amiloride (analog) occupied receptor; EIA, 5‐(N‐ethyl‐N‐isopropyl)amiloride; f, no displacement of orthosteric ligand by 100 µM amiloride (analog); g, [3H]CCR2‐RA‐[R] is an ‘intracellular antagonist’ as it binds intracellularly to the chemokine CCR2 receptor; HMA, 5‐(N,N‐hexamethylene)amiloride; H, human receptor; MGCMA, 5‐(N‐methyl‐N‐guanidinocarbonyl‐methyl)amiloride; i, in presence of 500 µM amiloride (analog); j, in presence of 3.16 mM amiloride (analog); k, in presence of 1 mM amiloride (analog); MIBA, 5‐(N‐methyl‐N‐isobutyl)amiloride; q, modulation by amiloride of acetylcholine‐induced contractions of rat tracheal smooth muscle, which expresses the muscarinic M3 receptor; R, rat receptor; m, inhibition by amiloride (analog) of dopamine‐stimulated increase in extracellular acidification rate in cells expressing the dopamine D2 receptor; n, inhibition by MIBA of dopamine‐stimulated [35S]GTPγS binding to dopamine D2 receptors; s, inhibition by amiloride of the sumatriptan‐induced reduction of cAMP formation stimulated by forskolin in cells expressing the Serotonin 5‐HT1B receptor; SEM, standard error of mean.
IC50 values determined with concentrations of orthosteric radioligands around their KD.
In presence of 100 µM amiloride (analog) except when stated otherwise.
[3H]CCR2‐RA‐[R] is an ‘intracellular antagonist’ as it binds intracellularly to the chemokine CCR2 receptor.